1. Technical Field
The present invention relates to a polyacetal resin composition for fuel-related parts comprising a polyacetal resin, glass fibers, a conductive carbon and a polyurethane resin, and having an excellent creeping resistance, a high conductivity and a high thermal stability in the kneading or molding step. It is also relates to fuel-related parts produced therefrom.
2. Background Art
A polyacetal resin is excellent in mechanical properties, fatigue resistance, friction and abrasion resistance, chemical resistance, oil resistance, thermal resistance and moldability. Therefore, it is used in a wide variety of fields such as automobiles, electrical and electronic equipment, other precision machines, and pipes for construction materials. As its use applications become wider, resin compositions having improved properties as materials are required and manufactured. As one of those resin compositions, a polyacetal resin containing a conductive carbon black for the purpose of giving conductivity thereto is used. For example, the polyacetal resins are used as fuel-related parts in consideration of their excellent chemical resistance. But in this case, since static electricity is generated by shearing of a fuel and the resin, the polyacetal resin is required to be conductive. Accordingly, the conductive carbon black is usually blended with the polyacetal resin.
However, the polyacetal resin has such a serious drawback that the blend of the carbon black noticeably decreases the toughness of the polyacetal resin. And so, when a pipe or the like as the above fuel-related part is continuously given a constant pressure or continuously loaded with a stress, a creep rupture occurs in a short period of time even if the stress is low.
On the other hand, in order to give the polyacetal resin both conductivity and a high mechanical strength, a surface-treated carbon fiber is added thereto. Such a polyacetal resin, however, cannot be used as general-purpose materials due to a highly increasing cost.
Therefore, there has been desired a polyacetal resin composition for fuel-related parts which can be manufactured at a low cost and which has a high conductivity, a high toughness, and in particular, an excellent creep resistance.